Between May and July 1918, the Spanish Flu, devastatingly lethal, infected more than two thirds of the population of Madrid. Ten thousand Madrilenians died in front of the authority’s inaction, who either did not know how to deal with the pandemic, or specifically avoided to do it. Nothing compared to what would come later, in the second wave, during the following autumn. Manuel Santos, an obsessive and misanthropic doctor, discovers how to stop the virus by applying social distancing measures. But he comes up against a wall in the Spanish business and political elites, because no one wants panic to set in and economic and commercial activity to come to a standstill.